1. Field of the Invention
The present invention relates to an apparatus for collection, storage and processing of biopsy specimens. The device cuts and captures a biopsy specimen with a closely defined size to permit entry into a storage cassette for subsequent processing.
2. The Prior Art
It is often necessary to obtain tissue samples for examination from deep within structures. These samples can only be retrieved by catheterization methods using endoscopic or fluoroscopic control, or by blind palpation. The biopsy devices used for these techniques remove 1 to 4 specimens that are retrieved by removing the biopsy instrument from the patient, and placing the specimen in a container of fixative solution labeled with the biopsy site and patient identification. The biopsies obtained in each pass are processed in a batch, since the minute pieces cannot be easily separated. Consequently, biopsies from different sites must be handled separately, thus requiring considerable effort and expense. Multiple biopsy passes are required because of the limited storage capacity of the biopsy instruments and the need to identify the sites of biopsy origin. This prolongs the procedure and may even cause it to fail, if the position of the biopsy instrument cannot be reacquired.
The batch of containers for each patient is then transported to the laboratory where the containers are serially opened and the specimens transferred to numbered cassettes that are recorded for later identification. The cassettes are then processed for examination. The processed specimens are then sliced, stained and mounted on labeled slides for microscopic examination. The specimens in each container must be processed separately to maintain identification. This is particularly important when the distribution and extent of a cancer is being mapped to determine the possibility of surgical removal and to prevent errors in reporting.
During this complex handling process, small specimens may be lost or damaged. At each stage of handling, the staff is exposed to possible infection from the biopsies, which is particularly true when the unfixed specimen is removed from the sharp biopsy instrument before it is fixed. The staff is also exposed to solvent vapor from the fixative at each transfer step of processing. The solvents may be allergenic or carcinogenic. This tedious, labor intensive process is also expensive both in terms of time and laboratory space.
Although the prior art has made biopsy deep within the patient possible, the need for additional improvements remains.
The storage and processing of multiple specimens within a biopsy instrument yields a great savings of time and effort in processing the biopsies, as well as preventing specimen loss or damage during handling. This goal is facilitated by applying redundant methods for forcing the minute biopsy specimens into a storage cassette of the biopsy instrument and by minimizing the operating parts of the biopsy instrument to maximize the storage volume.
The prior art described in the spring based multipurpose medical instrument in U.S. Pat. No. 5,782,747 to Zimmon, the disclosure of which is herein incorporated by reference, obviates the use of cumbersome metal shafts and coverings that occupy the space needed for specimen storage. Standard jaw fulcrum biopsy devices require a stiff shaft to prevent kinking and binding within the endoscope when the actuator cable(s) is pulled to close the biopsy jaws and then held to maintain jaw closure when removing the device and biopsy from the endoscope or access passage. The combined stiffness of the shaft and pull on the actuator cable(s) straightens the biopsy device and endoscope. This action moves the endoscope and biopsy device away from the biopsy site and limits maneuverability. This stiffness and uncontrolled motion also risks trauma to the biopsy site and limits access in curved lumens. A further limitation of stiff shafts is that they reduce the options for carrier instrument flexibility and maneuverability.
The closing force of a traditional forceps biopsy instrument is limited by a shaft length ranging from 100 cm to 220 cm and the multiple curves traversed within the endoscope that must conform to a lumen. Because of these disabilities, endoscopic biopsy forceps that are 5 to 9 French in diameter rip the mucosal biopsy from the muscularis mucosa. This gives a biopsy that is larger than the forceps cup and varies in size. Furthermore, tissue distortion from biopsy trauma may make histopathologic interpretation difficult.
U.S. Pat. Nos. 5,685,320 and 5,782,747, both to Zimmon, both of which are herein incorporated by reference, solve this problem by sharply cutting a biopsy of defined size that is suitable for passage through the tube shaft to an external receptacle. In U.S. Pat. No. 5,782,747, the distance between the central actuator wire and the cutting blade controls biopsy depth. Consequently, biopsy depth is less than one half of the shaft diameter. Actuator wire movement that limits the length of the cutting notch controls biopsy length. Width of the tangential biopsy is less than one half the tube shaft circumference. The cut biopsy is then captured within the tube shaft at the time of biopsy and therefore available to move into the external collection cassette.
In U.S. Pat. No. 5,685,320, the spring based multi-purpose medical instrument compresses folded spring sharp biopsy cups by sliding the tube shaft over a folded spring. The actuator wire only serves to hold the folded spring blade in biopsy position during biopsy cutting. The closed biopsy cups both cut and capture a biopsy of controlled size that is matched to the tube shaft and therefore available to move into the storage cassette.
The motive force of suction or fluid pressure propels the precisely cut biopsy from either device into the distal collection cassette as described in U.S. patent application Ser. Nos. 08/936,145, and 08/197,373 the disclosures of which are also herein incorporated by reference.